Prospective association between cumulative average grip strength and successful aging: evidence from the CHARLS, ELSA and SHARE multi-cohort study

Global population aging is accelerating, making successful aging a key public health goal. Grip strength, a functional biomarker, may reflect long-term muscle function and influence successful aging. Prior studies were limited by single-point exposure measurement and cross-population comparability. Based on data from three large international longitudinal aging cohorts—CHARLS, ELSA, and SHARE—we employed a two-stage temporal design, conducting independent analyses within each cohort using harmonized protocols, followed by random-effects meta-analysis to combine cohort-specific effect estimates. Cumulative average grip strength was computed from dominant hand grip strength measured at baseline and two follow-up waves using trapezoidal weighting. Successful aging was assessed 2–3 years after the exposure window at the outcome wave among participants aged ≥ 60 years. Individuals who already met successful aging criteria at baseline were strictly excluded (final N = 20,948). Progressive multivariable logistic regression with full covariate adjustment was conducted, complemented by propensity score matching and multiple sensitivity analyses. Cumulative average grip strength was consistently and positively associated with successful aging across all three cohorts. In the fully adjusted model (Model 3), each 1 kg increase in cumulative average grip strength was associated with 6.1% higher odds of successful aging in CHARLS (OR = 1.061), 2.1% higher odds in ELSA (OR = 1.021), and 5.2% higher odds in SHARE (OR = 1.052). Quantile analysis revealed significant dose-response gradients. Sensitivity analyses generally supported the robustness of the main findings. Cross-cohort meta-analysis further confirmed the positive association: the pooled OR was 1.043 (95% CI: 1.021–1.066) per 1 kg increase, and 1.543 (95% CI: 1.245–1.913) per 1 standard deviation increase. Greater cumulative muscle function exposure in middle-aged and older adults may facilitate successful aging. Consistent effects across countries suggest generalizability.